Exhibit 23.1 CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS As independent public accountants, we hereby consent to the incorporation of our report included in this Form 10-K, into the Company's previously filed Registration Statement File No. 33-64878 on Form S-8, 33-89820 on Form S-8, 33-99946 on Form S-8, 333-00358 on Form S-3, 333-03928 on Form S-8, 333-10481 on Form S-4, and 333-19301 on Form S-3. ARTHUR ANDERSEN LLP Chicago, Illinois March 28, 1997